Dubuffet waited until he was forty to devote himself to art. A man of intelligence, he chose to paint childlike images that combine a bold handling of texture with a wry, dark sense of humor. He considered his art rough, direct, and unfashionable. As an artist, he did not seek to please. The subjects of his early paintings are city streets of no historic interest, ordinary people performing everyday tasks, and likenesses of friends. He also examined with naive wonderment ordinary appliances such as the telephone, typewriter, and even a dentist's tool.

Dubuffet frequently watched his wife as she sat and cranked the handle of a coffee grinder gripped between her knees. The subject, frontally viewed, became a theme for a lithograph and for several drawings and paintings. The final version, however, bears slight resemblance to Lily, who was dark-haired, angular, and thin. Dubuffet flattened the head and broadened the body so that the hieratic figure completely fills the picture frame. He silhouetted this pale form against a somber background, actually a relief built with droppings, lumps, and furrows, combined into a substance that he described as "earth fermented by water." Dubuffet finished Woman Grinding Coffee on Christmas Day 1945. It is, perhaps, his earliest masterwork.